Optimization and Analysis of Possible Column Arrangements for Multicomponent Separations by Preparative Chromatography

Abstract

The optimal arrangement of eight identical chromatographic columns for the isolation of the intermediate adsorbing component of a ternary mixture is investigated theoretically. The arrangements considered are batch chromatography with columns connected in series and/or in parallel, cascades of two standard simulated moving bed (SMB) processes, and combinations of standard SMB units and batch columns. Based on standard column models, the productivity of each configuration was maximized by optimizing the relevant operating parameters using a modified simplex algorithm. The methodology applied allows us to evaluate all possible batch column arrangements on the basis of only eight different optimization runs. The results obtained reveal a significant dependency of the optimal process configuration on relevant aspects such as product purity, feed composition, and particle size of the adsorbent.

A Modular Framework for the Modelling and Optimization of Advanced Chromatographic Processes

“…This is the reason attaining cyclic steady-state takes several (here, four) cycles. Overall, the result appears plausible, since it is typical for such optimized scenario with limited purity requirements (see for example [11]). The fractionation of the last cycle of the optimized process is shown in Figure 6 (right).…”

“…Both gradient-based non-linear programming (NLP) solvers (e.g., interior-point algorithms [30], sequential programming [29], or simplex [11]) and derivative-free approaches (e.g., genetic algorithm [31] and Gaussian process regression [32]) were used successfully for optimal process design. Moreover, mixed-integer non-linear programming (MINLP) was applied to general process optimization using extended cutting plane algorithms [33], as well as for structural decision variables using outer approximation [34], and evolutionary algorithms [35].…”

“…If purity requirements are limited, bypass streams can be advantageous [9]. Moreover, the use of multiple columns gives rise to various concepts ranging from clever series or parallel arrangements of multiple batch columns [10,11], over pseudo-continuous processes, up to the many variants of the powerful continuous simulated moving bed (SMB) concept. Details on such advanced chromatographic operating modes are given, for example, in [2,3,12].…”

Advanced Operating Strategies to Extend the Applications of Simulated Moving Bed Chromatography

“…Using such a process, not only ternary mixtures can be treated, but, more importantly, a so-called center cut separation can be performed to isolate a certain target component out of a pseudo-ternary mixture. Evidence for intensive research can be found in several publications, which suggest different configurations for solving this difficult problem [140][141][142][143][144][145][146][147][148][149][150]. However, the application of such advanced SMB processes for the separation of complex mixtures is still exceptional.…”

Productivity of a preparative high‐performance liquid chromatography isolation of anacardic acids from cashew nut shell liquid

“…In the other hand, the use of preparative scale stands out as a versatile and fast tool capable to isolate high‐purity bioactive compounds from complex mixtures such as plant extracts . One of its fundamental characteristics is the possibility of injection of high volumes or concentrations , besides that this scale might use a high flow rate leading to a higher pressure, allowing to obtain purified compounds in a larger scale, resulting in a higher productivity and lower process costs . However, this scaling‐up should be done sparingly, since loading column capacity may affect separation performance causing compounds coelution due to the column saturation.…”